Low-dose interferon-alpha in stage-I multiple myeloma and in IgM monoclonal gammopathy. Eastern Cooperative Study Group on Monoclonal Gammopathies.

Interferon (IFN)-alpha can induce objective responses in advanced-stage multiple myeloma (MM) and can delay disease progression in patients responsive to chemotherapy. We studied the effects of low-dose (3 MU daily) human recombinant IFN-alpha 2b for 6-12 months in 29 consecutive cases of previously untreated, stable-phase, early stage, monoclonal gammopathy (MG) (23 cases of stage I MM and six cases of IgM MG). In 25/29 patients, the disease remained stable throughout the study period. A major objective response was observed in one of five cases of IgA MG. Normal Ig levels increased in all five cases of IgA MG. A significant disease progression occurred in 2/29 cases during the 1-year study period. These data showed that the objective response rate of early-stage MG to low-dose IFN was low and suggested that further investigation should focus on IgA MG.